Biocompatible oligomer-polymer compositions

A flowable composition comprising:

• (i) a biodegradable thermoplastic polymer that is at least substantially insoluble in body fluid,
• wherein the polymer is a poly(DL-lactide-co-glycolide) (PLG) without a carboxy terminal group, wherein the polymer without a terminal carboxyl group is optionally extended with a C2 to C12 diol and wherein the biodegradable thermoplastic polymer is a non-hydrolyzed PLG low-burst copolymer polyester material having a weight average molecular weight of about 10 kilodaltons to about 50 kilodaltons, a polydispersity index of about 1.4 to about 2.0, and from which a copolymer fraction having a weight average molecular weight of about 4 kDa to about 10 kDa and a polydispersity index of about 1.4 to about 2.5 has been removed;
• (ii) a biocompatible end-capped oligomeric liquid at ambient temperature of the formula I, II, III, IV, or V:
• wherein:
• each R1 is independently (C1-C12)alkyl, or (C1-C12)alkylenecarboxylic(C1-C12)alkylester;
• each R2 is independently (C1-C12)alkyl, carbonyl(C1-C12)alkyl, or carboxylic(C1-C12)alkylester;
• each R3 is independently (C1-C12)alkylene;
• R4 is (C1-C12)alkylene, carbonyl(C1-C12)alkylcarbonyl, or (C3-C12)cycloalkadiyl;
• R5 is (C1-C12)alkatriyl or (C3-C12)cycloalkatriyl;
• R6 is (C1-C12)alkylene, (C1-C12)alkyne, (C3-C12)cycloalkadiyl, (C1-C12)alkatriyl, or (C3-C12)cycloalkatriyl;
• R7 is (C1-C12)alkylene or (C1-C12)alkatriyl,
• X is absent or oxygen;
• W is absent, carbonyl, carbonyloxy, or oxycarbonyl;
• and
• any alkyl or alkylene of R1, R2, R3, R4, R5, R6 and R7 can optionally be substituted on carbon with one or more oxo, hydroxy, halogen, nitro, cyano, (C1-C12)alkyl, (C1-C6)alkoxy, trifluoromethyl, and optionally interrupted on carbon with one or more oxy, imino, or thio, and is optionally partially unsaturated;
• and
• each a, b, c, and d is independently 0, 1, 2, 3, 4, or 5;
• wherein the oligomeric liquid is of low water solubility to water insolubility, forming an aqueous solution of no more than 5% by weight in water;
• and
• (iii) a bioactive agent, a metabolite, or a prodrug thereof;
• wherein the composition does not comprise an organic solvent or an oligomeric liquid comprising free carboxyl and free hydroxyl groups.